OSI Systems (OSIS-8.2%) slips after saying its security division, Rapiscan Systems - which makes body scanning machines used in U.S. airports - expects to receive a proposed debarment notice from the Department of Homeland Security in connection with a Show Cause letter issued by agency regarding the termination of their software deal several months ago. The notice opens the first phase of formal proceedings that will allow Rapiscan to provide information and communicate directly with DHS officials.